Are you up for a day trip???? Yes, there's plenty to see and do in Dublin, and I mean no offense to Dublin locals here----but for me (and I know many others) getting out of the city and seeing the incredible scenery of the Irish countrysides or coastlines was awesome.
There's a couple of outfits that do day tours, so a little Googling around will help. You could do a day trip to Ireland's southeast region of Counties Wexford, Waterford and Kilkenny. You could do one up to Belfast, and catch an interesting black taxi tour there. Or, you could snag a day trip thru the beautiful Wiklow Mountains area.
I'd recommend either a day tour or renting a car yourself and taking in the Cliffs Of Moher (incredible!) and Galway Bay, Burren, etc.
If you're not confined to Dublin for both days--free to overnight between the two days somewhere else--that's deifnitely something to consider.